Terpolymers of acrylamide, acrylic acid and acrylonitrile: further characterization and biodegradation studies

Mathakiya I., Vangani V., Rakshit A.K.

Free-radical solution terpolymerization of acrylamide, acrylic acid, and acrylonitrile was carried out in a mixture of dimethylformamide and water (60 : 40,v/v) at 85°C using benzoyl peroxide as the initiator. The polymers were characterized by elemental analysis, IR, 1H-NMR, TGA, and viscosity measurements. Elemental analysis data were used to evaluate the terpolymer composition. The reactivity ratios were determined by Fineman–Ross and Kelen–Tudos methods. The reactivity ratios (r) for the copolymerization of (1) acrylic acid + acrylonitrile with (2) acrylamide was found to be r1 = 0.86 ± 0.09 and r2 = 1.93 ± 0.03, respectively, by the Kelen–Tudos method. The Fineman–Ross method yielded a value of r1 = 0.86 ± 0.05 and r2 = 1.94 ± 0.09, respectively. The activation energy values for various stages of decomposition were calculated from TGA analysis. Voluminosity (VE) and the shape factor (ν) were also computed from the viscosity measurements in different ratios of the solvent mixture. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 217–228, 1998

Rangaraj A., Vangani V., Rakshit A.K.

Homopolymers and copolymers of acrylamide (AA) and acrylic acid (AAc) were synthesized by the free radical solution polymerization technique. Feed ratios of the monomers were 85 : 15 (w/w), 65 : 35 (w/w), and 50 : 50 (w/w) of acrylamide and acrylic acid, respectively, for synthesis of copolymers. All reactions were carried out in aqueous media, except for the synthesis of polyacrylic acid, where the medium was n-butanol. Hydrogen peroxide, potassium persulfate, and benzoyl peroxide were used as initiators. The copolymers were purified by removing homopolymers. The homopolymers and copolymers were characterized by infrared (IR), 13C-nuclear magnetic resonance (NMR), 1H-NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and viscosity measurements. The fusion temperature and the energy change for various phase transitions were obtained from DSC measurements. The activation energy values for various stages of decomposition were calculated from TGA. The activation parameters for the viscous flow (i.e., free energy, enthalpy, and entropy of activation) were evaluated from the viscosity measurements. Voluminosity and Simha shape factor were also calculated for different systems. Effects of various concentrations of electrolytes, NaNO3, and Al(NO3)3 on viscosity behavior were studied. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 45–56, 1997

Nakamiya K., Ooi T., Kinoshita S.

The hydroquinone peroxidase of the lignin decolorizing bacterium, Azotobacter beijerinckii HM121 degraded 1 g/ l of polyacrylamide ( M r 2,000,000) to small molecules ( M r less than one thousand) in 30 min in the presence of 5 mM hydrogen peroxide and 5 μM tetramethylhydroquinone. The two reaction products were purified, and identified as 1-dodecene-2, 4, 6, 8, 10-pentacarboxyamide and 1-hexadecene-2, 4, 6, 8, 10, 12, 14-heptacarboxyamide comprising 5 and 7 acrylamide units, respectively. The enzyme also degraded 1 g/ l of polyacrylic acid ( M r 450,000) in 1 h, 1 g/ l of polyethylene glycol ( M r 4,000,000) in 1 h, and 1 g/ l of polyvinyl alcohol ( M r 88,000) for 20 h. The degradation rate decreased with a decrease in the degree of polymerization of the polyethylene glycol from M r 20,000 to 400. In addition 1 g/ l of polyethylene glycol ( M r 4,000,000) was degraded in the absence of tetramethylhydroquinone, although it took 20 h.

Bajaj P., Sen K., Bahrami S.H.

Solution copolymerization of acrylonitrile (AN) with various vinyl acids, i.e., acrylic acid (AA), methacrylic acid (MAA), and itaconic acid (IA), was carried out in DMF at 70°C using α,α′-azobisisobutyronitrile (AIBN) as an initiator with an acidic monomer of 0.012–0.092 mol %. Copolymers were characterized by FTIR, CHN analysis, 1H-and 13C-NMR, and viscometry. The reactivity ratios were calculated using Fineman–Ross and Kelen–Tudos methods. In all three systems, the value of r1 (AN) is much less than the value of r2. However, the r2 (MAA) is higher than r2 of (AA) and (IA). The reactivity ratios were calculated using Q and e schemes also. The results are in good agreement with experimentally calcualted data. The tacticity and sequence length distribution of these copolymers were calculated using 13C-NMR from CN and CH signals. It was observed that the isotacticity of acrylonitrile–itaconic acid copolymer P(AN–IA) with 8.2 mol % of a comonomer is lower than that of P(AN–MAA) with 10.3 mol % and P(AN–AA) with 7.61 mol %. © 1996 John Wiley & Sons, Inc.

Shukla P., Srivastava A.K.

Solution terpolymerization of styrene, acrylonitrile and chromium acrylate has been carried out in dimethylformamide at 85°C using styrene-arsenic sulfide complex as radical initiator. 1H nuclear magnetic resonance (n.m.r.), infra-red (i.r.) and elemental analysis have been used to characterize the terpolymer. Data from 1H n.m.r., elemental analysis and gravimetric analysis have been used to evaluate terpolymer composition. Reactivity ratios (calculated from Finemann-Ross method as r1(Sty) = 5 ± 2 r2(AN + CrA) = 0.15 + 0.02) and composition confirm its random origin. The terpolymer was highly thermally stable and has a glass transition temperature of 96°C as evaluated from differential scanning calorimetry studies.

Hu D.S., Lin M.T.

The water uptake and swelling behaviour of physically crosslinked, inhomogeneous poly(acrylonitrile-acrylamide-acrylic acid) hydrogels from 10 to 60°C were determined by gravimetry/differential scanning calorimetry and volume measurement, respectively. The contents of water and its non-bound portion were found to reach a minimum value at acrylamide content around 33.5 mol%, at which the water uptake of this gel does not vary with the temperature. The non-bound water was found to decrease gradually and then increase with increasing amide concentration. The duration of the post-gelation treatment between − 10 and 10°C was also shown to be one of the factors affecting the extent of the water uptake in gels. The critical endpoint temperatures ( T c s) of hydrogels, obtained from volume phase transition data upon changing the acetone concentration in aqueous solutions at various temperatures, were shown to decrease with the increasing acid or amide contents. The water uptake for gels with lower amide contents decreases with increasing temperature. However, there is an opposite trend for water uptake in gels with higher amide content, and the critical points on the plots of the amount of water uptake versus temperature appear at a temperature equal to T c .

Kawai F., Igarashi K., Kasuya F., Fukui M.

A possible aerobic degradative pathway for polyacrylate was examined with trimer (1,3,5-pentane tricarboxylic acid; PTCA)-utilizing bacteria. A few metabolic products from PTCA accumulated in culture filtrates and reaction mixtures of washed cells. Fraction A was detected as a main metabolite by high-performance liquid chromatography. A small amount of fraction B was concomitant with fraction A. Another fraction, C, was also detected. These compounds were suggested by liquid chromatography-mass spectrometry analyses to be 1,3,5-(1- or 2-pentene)tricarboxylic acid (fraction A or B) and 1,3,5-(2-oxopentane)tricarboxylic acid (fraction C). Fraction A was quickly further metabolized by washed cells, but fraction B was only gradually degraded. From these results, the metabolic pathway for polyacrylate is suggested to be quite similar toβ-oxidation for saturated fatty acids. The degradation of PTCA by washed cells was slower than that by growing cells and was inhibited by 5 mM NaN3. This suggests that the metabolism is linked to a respiratory chain or energy-producing system of bacteria which can aerobically assimilate PTCA.

Bajaj P., Goyal M., Chavan R.B.

The thermal degradation behavior of copolymers of methacrylic acid (81.5–17.4 mol%) was studied using thermogravimetry (TGA) and differential scanning calorimetry (DSC) and the degradation products were analyzed using mass spectroscopy and DSC–FTIR. From mass spectroscopy, it was observed that in the copolymers the main degradation products obtained below 280°C included water, ethanol, and methanol, whereas at higher temperature (up to 400°C), CO2, CO, and small olefins were liberated. Elimination of water and ethanol is attributed to anhydride formation, which is believed to result from two routes: (a) anhydride formation involving adjacent acid groups and (b) anhydride formation involving adjacent acid and ester groups. An endothermic transition in the DSC and percent weight loss in the TGA in the same temperature range (140–280°C) support the above proposal. An increase in weight loss with increase in EA content of the copolymer confirms the participation of EA in the anhydride formation. © 1994 John Wiley & Sons, Inc.

Albertsson A.

Chapatwala K.D., Hall E.M., Babu G.R.

Pseudomonas putida, capable of utilizing acetonitrile as a sole source of C and N, was immobilized in calcium alginate and the rates of degradation of nitriles, including acetonitrile, and their respective amides were studied. All the organic nitriles and amides tested were converted into NH3 and CO2.

Prasad J.V., Satpathy U.S., Jassal M., Pantar A., Satish S.

The free radical polymerization method has been employed to synthesize homopolymers of acrylonitrile (AN), its copolymers with methylacrylate (MA) and terpolymers containing itaconic acid (IA) in homogeneous solution (aqueous solution of sodium thiocyanate and dimethylsulfoxide media) and aqueous redox slurry system. 13C NMR was used to characterize these polymers in terms of steric configurations in order to study the effect of co and ter monomers on microstructure of polyarylonitrile both at low and high conversions. The study showed no significant change in microstructure of polyacrylonitrile on the introduction of MA and IA. Different techniques of polymerization for ACN-MA-IA had no effect on the microstructure of terpolymer. 1H NMR and IR techniques were used to determine the composition of copolymers and a good agreement was observed between the results from the two techniques. The presence of unsaturated carboxylic acid monomer (IA) was confirmed by 1H NMR.

Hocking P.J.

Abstract The current crisis in municipal solid waste disposal has created much public interest in the subject of degradable polymers and has led to some misconceptions as to how great a role these materials could play in solving the problem. Some people see these materials as the ideal solution whereby all plastics would magically disappear the instant their useful lives were over, and the entire waste disposal problem would be solved [l]. Politicians faced with the need to act on the issue find it easier to legislate degradability requirements than to set up the required infrastructure to deal with waste in a more productive way [l, 2]. Corn producers and others who see these laws creating new and larger markets for their products eagerly support these activities [l-4]. Thus there has been a flurry of activity in this area, with legislation forcing degradability in various products [5,6] and manufacturers hurrying to gain their share of these newly-formed markets.

Mahmoud A.A., Shaaban A.F., Khalil A.A., Messiha N.N.

Ternary copolymerization reactions of N-acryloyloxyphthalimide (NAP) or N-methacryloyloxyphthalimide (NMP) and acrylonitrile with methyl acrylate or methyl methacrylate were carried out in solution at 60°C in the presence of a free radical initiator. Experimental terpolymerization data agree well with calculations based on the Alfrey-Goldfinger equation. The determination of unitary, binary, and ternary azeotropies of the various systems studied was easily handled by a computer program. The results show that there is no ternary azeotropic composition for any terpolymer system studied. Selective unitary and binary azeotropic compositions were polymerized and the results show good agreement between the theoretical and experimental terpolymer composition in each case. The estimation of terpolymer compositions was carried out by 1H NMR spectroscopy.

Rittmann B.E., Sutfin J.A., Henry B.

Polyacrylate (PA), which is widely used in disposable diapers, is synthesized by polymerization and cross-linking of acrylate. During the synthesis, 3–6% of the polyacrylate polymers is not incorporated into the absorbent material, but remains soluble. If the soluble PA is mobilized from a landfill, it could enter the groundwater. Therefore, the biodegradation and adsorption properties of soluble polymers contained in PA are determined in this study. The soluble PA is highly polydisperse, and the fraction tested has a weight-average molecular-weight of 16,700 and a range extending from 103 to 105. Sand-column tracer tests show that about 1% of the polyacrylate is unadsorbed, but the remainder has a retardation factor that averages at least 58. Biodegradation kinetics are determined in completely mixed biofilm reactors having a methanogenic consortium grown on glucose. The polyacrylate fraction, as well as glucose and acrylate, are removed and mineralized to CO2. The Monod parameters for the polyacrylate are: maximum specific rate of substrate utilization = 0.0016 gC/g biomass-day, and half-maximum-rate concentration = 0.79 gC/m3. Although these kinetics are much slower than for glucose and acrylate, significant degradation and mineralization are observed.

Maurer J.J., Eustace D.J., Ratcliffe C.T.

Kong L., Zhao J., Cheng T., Lin J., Liu G.

The design of a smart heterogeneous catalyst for controllable reaction switching is highly desirable in asymmetric catalysis. In this work, by taking advantage of the thermoresponsive behavior of a water-soluble polymer coating and the confined feature of silica nanoparticles, we have constructed a silica material with chiral rhodium/diamine functionality on SiO2 nanospheres coated with a water-soluble thermoresponsive polymer. The solid-state 13C NMR spectrum of the product demonstrated well-defined single-site chiral rhodium active centers within the thermoresponsive polymer, and scanning electron microscopy and transmission electron microscopy revealed its uniformly dispersed morphology. As a smart heterogeneous catalyst, it enables catalyst-based temperature-controlled reaction switching in the enantioselective tandem reduction–lactonization of ethyl 2-acylarylcarboxylates in water. At 40 °C, the catalyst promotes highly enantioselective tandem reduction–lactonization by adopting the extended form of ...

Chauhan N.P.

A novel class of linear terpolymer resins have been prepared from various macromers formed by vanillin oxime (VO), formaldehyde (F) and p-chloro/p-methylacetophenone in the presence of an acid as catalyst by convenient polycondensation process. The conversion of different macromers into respective terpolymeric resin was studied by DSC analysis from −50 °C to 250 °C. The first thermal transition endotherms ranging from 108–137 °C (VOFCA) and 125–150 °C (VOFMA) are due to expulsion of water molecules, and the second thermal transition exotherms 177–247 °C (VOFCA) and 183.9–249.8 °C (VOFMA) are attributed to the formation of methylene linkage between macromers moieties by utilizing methlol groups at terminals. The activation energy required for conversion of methylol into methylene groups for VOFCA and VOFMA was 3.4 and 3.9 kJ/mol, respectively. Structural confirmations were determined through IR, Uv-Vis, 1H NMR spectroscopy and GPC data. The activation energy (Ea) and thermodynamic parameters of the thermal decomposition process were investigated with thermogravimetric analysis (TGA) by isoconversional integral Kissinger-Akahira-Sunose (KAS) and differential Friedman methods. Empirical kinetic models, as well as generalized master plots, were applied to explain the degradation mechanisms of terpolymer resins. The degradation reaction follows Avrami-Erofeev (nucleation and growth) at initial stage to Jander (three-dimensional diffusion) model for PVOMAF and Jander (two-dimensional diffusion) for PVOFCA governed mechanisms. Among all the tested terpolymers, both resins revealed better activity compared to standard drugs as Gentamycin, Amphicilin, Chloramphenicol, Ciprofloxacin and Noorfloxacin.

Nasr* H.E.

Mathakiya I.A., Rakshit A.K., Iyer B.D., Shah A.K.

Copolymers of tartaric acid with various diamines were synthesized by a condensation polymerization technique. The synthesized polymers were characterized by elemental analysis, FTIR, 1H-NMR, paper chromatography, TGA analysis, viscosity measurements and biodegradation studies. Elemental analysis, paper chromatography and spectroscopic studies confirmed polyamide formation. The activation energy values for various stages of decomposition were calculated from TGA analysis using Broido's method. The intrinsic viscosity ([η]), voluminosity (V E ) and shape factor (ν) were also computed using viscosity data. Microbiological observations of polymer-dependant growth studies using a soil bacterial isolate, suggested that one of these polymers was used as growth substrate and was therefore biodegradable.

Vasile C., Marinescu C., Vornicu R., Staikos G.

The enzymatic degradation of poly(N-isopropyl acrylamide) (PNIPAM) grafted to carboxymethylcellulose (CMC) copolymers with a cellulasic preparation (Trichoderma viride) was studied. The enzymatic activity of the cellulasic preparation against CMC and the grafted copolymers was determined by the Petterson–Porath method, while their reduced viscosity variation in the presence of the same preparation was also followed. It has been shown that the enzymatic degradation behavior depends on the copolymer composition and the reaction temperature. Reducing sugars analysis showed that the experimental values for the grafted copolymers were higher than the calculated ones. At 50°C, the enzymatic reaction is completed in about 20 min for the copolymers, whereas for CMC it takes more than 40 min. It can be concluded that their enzymatic degradation is facilitated by the presence of the PNIPAM grafts. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1383–1386, 2003